In a single step, 5 mL i-Pr trans-cinnamate dissolved in Me2CO or 2-Me-2- or 2-propanol with (LiOH.H2O + K2OsO2 (OH)(4)) as catalyst was cis-dihydroxylated and simultaneously acetamidated with 4 g N-bromoacetamide at 25degreesC. In 20 h, Na2SO3 was added and, in 2 h, the product was extracted with AcOEt, hydrolyzed with 10% HCl, evaporated in vacuo, and purified by chromatography to yield 66-67% of 85.7-92.3% pure (2R,3S)-phenylisoserine hydrochloride, optical purity [alpha](D)(20) = -11.3degrees to -11.6degrees. In a multi-step procedure, Me trans-cinnamate and 4-methylmorpholine N-oxide (with the osmate and hydroquinine 1,4-phthalazinediyl diether added as oxidation and chiral catalysts, resp.) reacted 20-200 h in 2-Me-2-propanol as solvent at 25degreesC to yield the dihydroxy derivative, optical purity 99%. This treated with tri-Me orthoacetate and next with AcBr gave the Br-derivative with the configuration (at this C atom) inverted. Next, NaN3 was added to substitute the Br atom with the azide group, the configuration being re-inverted, and the derivative was reduced with H-2 in situ to insert the NH2 group at carbon 3 and to make the Ac migrate to yield methyl N-acetyl (2R,3S)-2-amino-3-hydroxy-3-phenylpropionate. The ester and the acetamide groups were hydrolyzed with 10% HCl to yield (2R,3S)-phenylisoserine hydrochloride. Three reported methods were critically reviewed.